Editing Wind power (section)

== Wind farms ==
{{main|Wind farm|List of onshore wind farms}}

{| class="wikitable floatright sortable"
|+ Large onshore wind farms
|-
! Wind farm
! Capacity<br />([[Megawatt|MW]])
! Country
! class="unsortable" | Refs
|-
| [[Gansu Wind Farm]] || align="center" | 7,965 || {{Flagu|China}} || <ref>Watts, Jonathan & Huang, Cecily. [https://www.theguardian.com/world/2012/mar/19/china-windfarms-renewable-energy Winds Of Change Blow Through China As Spending On Renewable Energy Soars] {{Webarchive|url=https://web.archive.org/web/20130615063412/http://www.guardian.co.uk/world/2012/mar/19/china-windfarms-renewable-energy |date=15 June 2013 }}, ''[[The Guardian]]'', 19 March 2012, revised on 20 March 2012. Retrieved 4 January 2012.</ref>
|-
| [[Muppandal Wind Farm]]|| align="center" | 1,500 || {{Flagu|India}} || <ref>{{cite web|url=http://www.thewindpower.net/windfarm_en_449.php|title=Muppandal (India)|publisher=thewindpower.net|access-date=21 November 2015|archive-date=14 August 2014|archive-url=https://web.archive.org/web/20140814194848/http://www.thewindpower.net/windfarm_en_449.php|url-status=live}}</ref>
|-
| [[Alta Wind Energy Center|Alta (Oak Creek-Mojave)]] || align="center" | 1,320 || {{Flagu|United States}} ||<ref>[http://www.terra-genpower.com/News/Terra-Gen-Power-Announces-Closing-of-$650-Million-.aspx Terra-Gen Press Release] {{webarchive|url=https://web.archive.org/web/20120510173856/http://www.terra-genpower.com/News/Terra-Gen-Power-Announces-Closing-of-%24650-Million-.aspx |date=10 May 2012}}, 17 April 2012</ref>
|-
| [[Jaisalmer Wind Park]] || align="center" | 1,064 || {{Flagu|India}} ||<ref>[http://www.business-standard.com/india/news/suzlon-creates-country/s-largest-wind-park/164779/on Started in August 2001, the Jaisalmer based facility crossed 1,000 MW capacity to achieve this milestone] {{Webarchive|url=https://web.archive.org/web/20121001062608/http://www.business-standard.com/india/news/suzlon-creates-country/s-largest-wind-park/164779/on |date=1 October 2012 }}. Business-standard.com (11 May 2012). Retrieved on 20 July 2016.</ref>
|}

A wind farm is a group of [[wind turbine]]s in the same location. A large wind farm may consist of several hundred individual wind turbines distributed over an extended area. The land between the turbines may be used for agricultural or other purposes. A wind farm may also be located offshore. Almost all large wind turbines have the same design&nbsp;— a horizontal axis wind turbine having an upwind rotor with 3 blades, attached to a [[Nacelle (wind turbine)|nacelle]] on top of a tall tubular tower.

In a wind farm, individual turbines are interconnected with a medium voltage (often 34.5&nbsp;kV) power collection system<ref>{{cite web|url=https://ewh.ieee.org/r3/atlanta/ias/Wind%20Farm%20Electrical%20Systems.pdf|title=Wind Farm Electrical Systems|access-date=2020-07-11|archive-date=18 March 2021|archive-url=https://web.archive.org/web/20210318210221/https://ewh.ieee.org/r3/atlanta/ias/Wind%20Farm%20Electrical%20Systems.pdf|url-status=live}}</ref> and communications network. In general, a distance of 7D (7 times the rotor diameter of the wind turbine) is set between each turbine in a fully developed wind farm.<ref>{{Cite journal|last1=Meyers|first1=Johan|last2=Meneveau|first2=Charles|date=1 March 2012|title=Optimal turbine spacing in fully developed wind farm boundary layers|journal=Wind Energy|volume=15|issue=2|pages=305–17|doi=10.1002/we.469|bibcode=2012WiEn...15..305M|url=https://lirias.kuleuven.be/handle/123456789/331240|url-access=subscription}}</ref> At a substation, this medium-voltage electric current is increased in voltage with a [[transformer]] for connection to the high voltage [[electric power transmission]] system.<ref>{{cite web|url=https://www.windpowerengineering.com/projects/making-modern-offshore-substation/|title=Making of the modern offshore substation|website=Windpower Engineering & Development|language=en-US|access-date=14 June 2019|archive-date=24 November 2021|archive-url=https://web.archive.org/web/20211124094304/https://www.windpowerengineering.com/making-modern-offshore-substation/|url-status=live}}</ref>

=== Generator characteristics and stability ===

Most modern turbines use variable speed generators combined with either a partial or full-scale power converter between the turbine generator and the collector system, which generally have more desirable properties for grid interconnection and have [[low voltage ride through]]-capabilities.<ref name="huang">{{Cite book|last1=Falahi|first1=G.|last2=Huang|first2=A.|title=IECON 2014 – 40th Annual Conference of the IEEE Industrial Electronics Society |chapter=Low voltage ride through control of modular multilevel converter based HVDC systems |date=1 October 2014|pages=4663–68|doi=10.1109/IECON.2014.7049205|isbn=978-1-4799-4032-5|s2cid=3598534}}</ref> Modern turbines use either [[doubly fed electric machine]]s with partial-scale converters or squirrel-cage induction generators or synchronous generators (both permanently and electrically excited) with full-scale converters.<ref>{{cite journal|doi=10.1016/j.enconman.2014.08.037|title=The state of the art of wind energy conversion systems and technologies: A review|journal=Energy Conversion and Management|volume=88|page=332|year=2014|last1=Cheng|first1=Ming|last2=Zhu|first2=Ying|bibcode=2014ECM....88..332C }}</ref> [[Black start]] is possible<ref>{{Cite web |date=2020-11-03 |title=ScottishPower in 'pioneering world first' after wind farm black-out boost |url=https://www.scotsman.com/business/scottishpower-in-pioneering-world-first-after-wind-farm-black-out-boost-3023563 |access-date=2022-09-19 |website=www.scotsman.com |language=en}}</ref> and is being further developed for places (such as [[Iowa]]) which generate most of their electricity from wind.<ref>{{Cite web |title=As the grid adds wind power, researchers have to reengineer recovery from power outages |url=https://www.sciencedaily.com/releases/2022/05/220531181931.htm |access-date=2022-09-19 |website=ScienceDaily |language=en}}</ref>

[[Transmission system operator]]s will supply a wind farm developer with a [[grid code]] to specify the requirements for interconnection to the transmission grid. This will include the [[power factor]], the constancy of [[Utility frequency|frequency]], and the dynamic behaviour of the wind farm turbines during a system fault.<ref>{{Cite journal | last1 = Demeo | first1 = E.A. | last2 = Grant | first2 = W. | last3 = Milligan | first3 = M.R. | last4 = Schuerger | first4 = M.J. | year = 2005 | title = Wind plant integration | journal = IEEE Power and Energy Magazine| volume = 3 | issue = 6 | pages = 38–46 | doi = 10.1109/MPAE.2005.1524619| s2cid = 12610250 }}</ref><ref>{{Cite journal | last1 = Zavadil | first1 = R. | last2 = Miller | first2 = N. | last3 = Ellis | first3 = A. | last4 = Muljadi | first4 = E. | year = 2005 | title = Making connections | journal = IEEE Power and Energy Magazine| volume = 3 | issue = 6 | pages = 26–37 | doi = 10.1109/MPAE.2005.1524618| s2cid = 3037161 }}</ref>

=== Offshore wind power ===
{{multiple image |total_width=500
|image1=Agucadoura WindFloat Prototype.jpg | caption1= The world's second full-scale [[floating wind turbine]] (and first to be installed without the use of heavy-lift vessels), WindFloat, operating at rated capacity (2&nbsp; MW) approximately 5&nbsp; km offshore of [[Póvoa de Varzim]], Portugal

|image2= 20210830 Windfarm power generation capacity - offshore capacity, and total needed.svg| caption2= Offshore windfarms, including floating windfarms, provide a small but growing fraction of total windfarm power generation. Such power generation capacity must grow substantially to help meet the [[International Energy Agency|IEA]]'s [[Carbon neutrality|Net Zero]] by 2050 pathway to combat [[climate change]].<ref name=Guardian_20210829>{{cite news |last1=Rosa-Aquino |first1=Paola |title=Floating wind turbines could open up vast ocean tracts for renewable power |url=https://www.theguardian.com/environment/2021/aug/29/floating-wind-turbines-ocean-renewable-power |work=The Guardian |date=29 August 2021 |archive-url=https://web.archive.org/web/20210830162300/https://www.theguardian.com/environment/2021/aug/29/floating-wind-turbines-ocean-renewable-power |archive-date=30 August 2021 |url-status=live }}</ref>
}}
{{Main|Offshore wind power|List of offshore wind farms}}

Offshore wind power is wind farms in large bodies of water, usually the sea. These installations can use the more frequent and powerful winds that are available in these locations and have less visual impact on the landscape than land-based projects. However, the construction and maintenance costs are considerably higher.<ref>{{cite web|url=http://www.renewables-info.com/drawbacks_and_benefits/offshore_wind_power_%E2%80%93_advantages_and_disadvantages.html|title=Offshore wind power&nbsp;– Advantages and disadvantages|last=Hulazan|first=Ned|date=16 February 2011|publisher=Renewable Energy Articles|access-date=9 April 2012|archive-date=13 October 2018|archive-url=https://web.archive.org/web/20181013053638/http://www.renewables-info.com/drawbacks_and_benefits/offshore_wind_power_%E2%80%93_advantages_and_disadvantages.html|url-status=live}}</ref><ref>{{cite web|url=http://www.windpowermonthly.com/go/europe/news/1021043/Cutting-cost-offshore-wind-energy/|title=Cutting the cost of offshore wind energy|last=Millborrow|first=David|date=6 August 2010|website=Wind Power Monthly|publisher=Haymarket|access-date=10 April 2012|archive-date=2 December 2012|archive-url=https://web.archive.org/web/20121202035902/http://www.windpowermonthly.com/go/europe/news/1021043/Cutting-cost-offshore-wind-energy/|url-status=live}}</ref>

As of November 2021, the [[Hornsea Wind Farm]] in the [[United Kingdom]] is the largest offshore wind farm in the world at 1,218 [[Megawatt|MW]].<ref name="hornsea">{{Cite web|date=2020-01-30|title=World's Largest Offshore Wind Farm Fully Up and Running|url=https://www.offshorewind.biz/2020/01/30/worlds-largest-offshore-wind-farm-fully-up-and-running/|url-status=live|archive-url=https://web.archive.org/web/20200131051635/https://www.offshorewind.biz/2020/01/30/worlds-largest-offshore-wind-farm-fully-up-and-running/|archive-date=31 January 2020|access-date=2020-02-03|website=Offshore Wind|language=en-US}}</ref>

=== Collection and transmission network ===
Near offshore wind farms may be connected by AC and far offshore by HVDC.<ref>{{Cite web |last=Action |first=BMWK-Federal Ministry for Economics Affairs and Climate |title=Connecting offshore wind energy to the grid |url=https://www.bmwk.de/Redaktion/EN/Artikel/Energy/connecting-offshore-wind-energy-to-the-grid.html |access-date=2023-01-20 |website=www.bmwk.de |language=en}}</ref>

Wind power resources are not always located near areas with a high [[population density]]. As transmission lines become longer, the losses associated with power transmission increase, as modes of losses at lower lengths are exacerbated and new modes of losses are no longer negligible as the length is increased; making it harder to transport large loads over large distances.<ref>Power System Analysis and Design. Glover, Sarma, Overbye/ 5th Edition</ref>

When the transmission capacity does not meet the generation capacity, wind farms are forced to produce below their full potential or stop running altogether, in a process known as [[Curtailment (electricity)|curtailment]]. While this leads to potential renewable generation left untapped, it prevents possible grid overload or risk to reliable service.<ref name=maine>[http://www.pressherald.com/news/there-is-a-problem-with wind-power-in-maine_2013-08-04.html?pagenum=full Inadequate transmission lines keeping some Maine wind power off the grid – The Portland Press Herald / Maine Sunday Telegram] {{Webarchive|url=https://web.archive.org/web/20211124094412/https://www.pressherald.com/2013/08/04/there-is-a-problem-withwind-power-in-maine_2013-08-04/ |date=24 November 2021 }}. Pressherald.com (4 August 2013). Retrieved on 20 July 2016.</ref>

One of the biggest current challenges to wind power grid integration in some countries is the necessity of developing new transmission lines to carry power from wind farms, usually in remote lowly populated areas due to availability of wind, to high load locations, usually on the coasts where population density is higher.<ref>{{Cite web|date=2021-04-07|title=From West to East: The Charged Challenge of Delivering Electricity|url=https://www.chinabusinessreview.com/from-west-to-east-the-charged-challenge-of-delivering-electricity/|access-date=2021-11-24|website=China Business Review|language=en-US}}</ref> Any existing transmission lines in remote locations may not have been designed for the transport of large amounts of energy.<ref name="nytimes.com">Wald, Matthew (26 August 2008) [https://www.nytimes.com/2008/08/27/business/27grid.html?pagewanted=all&_r=0 Wind Energy Bumps Into Power Grid's Limits] {{Webarchive|url=https://web.archive.org/web/20170701110101/http://www.nytimes.com/2008/08/27/business/27grid.html?pagewanted=all&_r=0 |date=1 July 2017 }}. ''New York Times''</ref> In particular geographic regions, peak wind speeds may not coincide with peak demand for electrical power, whether offshore or onshore. A possible future option may be to interconnect widely dispersed geographic areas with an HVDC [[super grid]].<ref>{{Cite web|last=Barnard|first=Michael|date=2021-11-11|title=Breaking News: China & USA Joint Declaration On Climate Action Collaboration|url=https://cleantechnica.com/2021/11/11/breaking-news-china-and-usa-joint-declaration-on-climate-action-collaboration/|access-date=2021-11-23|website=CleanTechnica|language=en-US|archive-date=12 November 2021|archive-url=https://web.archive.org/web/20211112143817/https://cleantechnica.com/2021/11/11/breaking-news-china-and-usa-joint-declaration-on-climate-action-collaboration/|url-status=live}}</ref>